A training instructor at one of my airlines shared this story: About 30 years ago, a Continental captain and first officer were on approach to Houston Intercontinental Airport (KIAH), at the end of an arduous pairing in which they failed to get along.
The two were arguing so loudly that the flight attendants could hear them through the cockpit door, and so loudly neither pilot heard the gear warning horn. They landed the DC-9 gear up.
It was a cautionary tale of a flight crew failing to compartmentalize their problems and adhere to the sterile cockpit rule. The instructor said the incident might have been a catalyst for the rule’s implementation in 1981.
He was wrong. Continental Flight 1943 was the only DC-9 to land gear up at KIAH in 1996. That was 15 years after the rule went into effect. And according to the transcripts I found online, the flight crew was discussing the captain’s tennis game and not engaged in a heated argument. Nevertheless, the instructor’s point remains valid.
Close to 500 pilots filed reports to NASA’s Aviation Safety Reporting System citing sterile cockpit rule violations as a causal factor. More than a third of those reports came from general aviation pilots.
That’s encouraging to read as the sterile cockpit rule is only legally applicable to Part 121 (scheduled air carriers) and Part 135 (commercial operators).
The number of GA pilots referencing lack of sterile cockpit discipline in their reports indicates how many general aviation pilots value the rule enough to adapt it for themselves.
More than two dozen of the reports were filed by an instructor or by a pilot receiving instruction during the reported event.
Too low while talking
An instrument flight instructor (CFII) in a C-182 busted an altitude restriction by descending prematurely to the course reversal altitude while demonstrating a non-precision approach for his student.
He flew his student from their base to Reedsburg Municipal Airport (C35) in Wisconsin to expose him to an unusual VOR-A approach.
Normally, non-precision approaches require a pilot to perform a procedure turn to lose altitude and/or get established on the final approach course. The Reedsburg VOR-A approach mandates a holding pattern at the Initial Approach Fix (IAF) if not vectored to the final approach course by ATC.
The CFII acknowledged that he was flying in instrument meteorological conditions (IMC), that he could not clearly see the altimeter from his right seat position, and that he was briefing an unfamiliar approach while also flying the same approach for the first time.
He also acknowledged that he quickly “got behind the plane.”
“I should have accepted a radar vector when asked, but I played macho and said I would do it all myself for the sake of training the IFR applicant,” he wrote.
When cleared for the approach, the Cessna CFII didn’t realize he was still seven miles from the IAF. He thought he was close enough to the published approach segment that he could descend to the holding pattern altitude of 2,700′. So he did.
Descending through 3,000′, ATC warned him that 3,200′ was the minimum vectoring altitude. He immediately climbed back to 3,500′ and completed the approach without further incident, while still giving dual instruction.
The instructor wrote that he continued his dual instruction narrative to educate the student about his mistake and how to avoid it.
He also wrote that he should have recognized how overloaded he was just with the normal tasks of flying an unfamiliar approach in IMC.
“That should have cued me to stop the dual narration and just demonstrate the approach until I caught up with all my tasks,” he reported.
The CFII blamed himself for failing to adhere to sterile cockpit procedures. But had he?
A Gear Up Landing
A multi-engine instructor (MEI) filed a NASA Report after he and a student landed gear up in a Piper Seminole. He too cited failure to maintain a sterile cockpit as the cause of the incident.
With the MEI monitoring, his student performed a single-engine, non-precision approach into Devils Lake Regional Airport (KDVL) in North Dakota wearing foggles. The MEI told his student to remove the foggles 200′ above Minimum Decision Altitude (MDA) and then to run the landing checklist.
Because the student didn’t, the instructor started the landing checklist for him.
Simultaneously, he told the student he could use the second engine should a go-around become necessary.
“At that point, I always check the gear to make sure it’s down and locked,” wrote the instructor. “However, I was distracted by the displaced threshold.”
Specifically, the instructor did not know if his student was aware of the displaced threshold.
He could not recall hearing the gear warning horn before contacting the runway.
The MEI attributed the incident to a failure to brief the student about the KDVL Runway 31 displaced threshold before starting the approach.
Like the C-182 CFII, he blamed himself for breaking “the sterile cockpit rule at such a critical phase of flight.” But had he, really?
Flight Instructors and the Sterile Cockpit Rule
These two reports represent the dilemma all flight instructors face when applying the sterile cockpit rule to actual flight instruction.
On the one hand, we’re taught a good flight instructor is supposed to be able to fly and talk simultaneously. On the other hand, how does that jibe with the rule?
CFR 121.542/135.100, “Flight Crewmember Duties” — aka the sterile cockpit rule — requires pilots to refrain from “nonessential activities” in the cockpit during critical phases of flight.
While critical phases of flight are precisely defined as “all ground operations involving taxi, takeoff and landing, and all other flight operations conducted below 10,000′ , except cruise flight,” the definition of nonessential activities is very broad.
The rule defines as nonessential “any activity during a critical phase of flight which could distract any flight crewmember…or which could interfere in any way with the proper conduct of those duties…for the safe operation of the aircraft.”
In the first half-century of flight, nonessential activity didn’t need definition because it was mostly nonexistent. Cockpits, motors, and wind noise were all too loud for normal conversation to occur. Also, pilots spent all their time concentrating on aviating, constantly assessing unreliable motors, listening for weak signals through lousy headsets, and monitoring navigational equipment whose most precise calibrations had a margin of error eight nautical miles wide.
In the second half-century of aviation, the reliability of engines, navigational equipment, noise-canceling headsets, and other technology allows pilots to spend more time on in-flight conversations than on keeping their aircraft aloft and on course.
That’s why the sterile cockpit rule exists. Reliability created the potential for complacency by aviators. The rule’s purpose is to recreate that heightened sense of situational awareness precisely when it’s needed.
I chose the NASA reports I did for this column because they represent the mindset of many flight instructors who believed failure to maintain a sterile cockpit was the source of their problems. My analysis of these reports reveals their problems may have stemmed from failure to be the pilot in command.
For the C-182 CFII, verbalizing the approach procedure while demonstrating the approach procedure was essential to instruction. Therefore it was an essential activity during a critical phase of flight.
In the case of the MEI, telling the student that he had use of the second throttle in a go-around was essential. So was performing some of the landing checks the student hadn’t.
The Cessna CFII didn’t descend too soon because of extraneous chatter or activity. He descended too soon because he hadn’t used his PIC authority to delegate tasks to others to help him regain situational awareness.
ATC tried to help the CFII by offering a heading that would help him get established on the final approach course, but he declined them. The primary flight instruments were partially blocked by the CFII’s right seat position, but he failed to enlist the help of his student to monitor them.
Likewise, the Piper MEI didn’t land gear up from too much activity or chatter. Rather it was from abdicating PIC authority when he started the landing checklist for his overwhelmed student but failed to complete it. If he had, he’d have lowered the gear.
He wrote that he wondered whether his student saw the displaced threshold, but then he didn’t say anything.
Flight instructors sometimes unwittingly give up their PIC authority in the interest of instructing. Something distracted the MEI from uttering one simple sentence, “Displaced threshold ahead.” It certainly would count as a sentence critical to that phase of that flight.
I think the FAA intentionally left the definition of “nonessential activity” vague because officials understood that every critical phase of flight is as different as every flight. The variability of the Earth’s atmosphere, the amount of aircraft activity in the National Airspace System, and human factors are the constants that assure this.
The sterile cockpit rule does not mean “no talking,” as one CFI indicated in his NASA Report. Nor does it mean “no deviations.”
It’s a reminder for us to stay sharp and focus on the basics — aviate, navigate, communicate —instead of thinking about our tennis game.